Lightweight sound insulation material and preparation method thereof

Abstract

The invention discloses a lightweight sound insulation material and a preparation method thereof, and relates to the technical field of sound insulation materials. The invention discloses a light sound insulation material. The electromagnetic shielding material is prepared from the following raw materials in parts by weight: 18-22 parts of modified polypropylene fiber, 12-16 parts of modified vermiculite powder, 3-5 parts of nano titanium dioxide, 8-12 parts of hollow glass beads, 6-8 parts of wollastonite powder, 4-6 parts of vinyl acetate-ethylene copolymer latex powder, 10-14 parts of a binder, 1-3 parts of a waterproof agent, 0.5-1.5 parts of a moisture permeable agent, 4-6 parts of electromagnetic shielding filler, 3-5 parts of a flame retardant and 1-3 parts of a dispersant. The lightweight sound insulation material has remarkable advantages. The light-weight sound-insulation and anti-aging floor integrates multiple functions of light weight, sound insulation, sound absorption, impact resistance, aging resistance, bacteria resistance and the like, and can effectively meet the requirements of different scenes. The preparation method is scientific, has clear process parameters, and can ensure stable and uniform material performance. And the raw materials are environment-friendly, so that a healthy and safe living and working environment can be created while noise is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sound insulation materials, and specifically provides a lightweight sound insulation material and a preparation method thereof. Background Art

[0002] In today's society, with the acceleration of the urbanization process and the improvement of people's living standards, the requirements for the comfort of living and working environments are increasing day by day, and the importance of sound insulation materials has become more prominent. In the field of architecture, high-rise buildings stand in cities, and traffic noise, neighborhood activity noise, etc. seriously affect the quality of life of residents. In commercial places, such as offices, meeting rooms, hotels, etc., good sound insulation effects can improve work efficiency, ensure the privacy of meetings, and provide a quiet rest environment for customers. In industrial production environments, the noise generated by the operation of machinery and equipment not only interferes with the normal operation of workers, but long-term exposure may also damage hearing health.

[0003] There are a variety of existing sound insulation materials, but most of them have certain limitations. Common sound insulation cotton, although it has a certain sound insulation effect, has a soft texture and poor mechanical properties. It is easy to deform when subjected to external extrusion or impact, and it is difficult to meet the application scenarios with requirements for structural strength. Moreover, sound insulation cotton usually does not have waterproof and fireproof properties. In humid environments or during fires, it not only cannot play a sound insulation role, but may also pose safety hazards. Some traditional sound insulation boards, such as wooden sound insulation boards, although they have advantages in terms of aesthetics and a certain degree of sound insulation performance, they are prone to moisture and mildew, have poor anti-aging performance, and have a short service life. Moreover, the fireproof performance of wooden materials is relatively weak, and their use is restricted in places with strict fireproof requirements. Metal sound insulation boards have high strength and good fireproof performance, but they are relatively heavy, which not only increases the cost and difficulty of transportation and installation, but also places higher requirements on the load-bearing structure of buildings. At the same time, metal materials are prone to corrosion, and during long-term use, their sound insulation performance may decline due to corrosion.

[0004] In addition, existing sound insulation materials often have relatively single functions and are difficult to simultaneously meet multiple requirements such as sound insulation, light weight, fireproof, waterproof, antibacterial, etc. In the current trend of modern material applications that pursue multi-functional integration, it is urgent to develop a lightweight sound insulation material with excellent comprehensive performance. The present invention aims to overcome the deficiencies of existing sound insulation materials and, through innovative raw material formulations and preparation processes, develop a new type of sound insulation material with multiple properties such as light weight, good sound insulation effect, impact resistance, anti-aging and corrosion resistance, environmental protection, heat insulation, fire retardancy, antibacterial, moisture permeability, electromagnetic shielding, etc., to meet the growing needs of different fields. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a lightweight sound insulation material and a preparation method thereof, which solve the above problems.

[0006] To achieve the above object, the present invention is realized by the following technical solutions: A lightweight sound insulation material, comprising the following raw materials in parts by weight: 18-22 parts of modified polypropylene fiber, 12-16 parts of modified vermiculite powder, 3-5 parts of nano-titanium dioxide, 8-12 parts of hollow glass microspheres, 6-8 parts of wollastonite powder, 4-6 parts of ethylene-vinyl acetate copolymer latex powder, 10-14 parts of binder, 1-3 parts of waterproofing agent, 0.5-1.5 parts of moisture permeable agent, 4-6 parts of electromagnetic shielding filler, 3-5 parts of flame retardant, 1-3 parts of dispersant.

[0007] Further, the preparation steps of the modified polypropylene fiber are as follows: A1. Soak the polypropylene fiber in an acetone solution for 4 hours, stir at a speed of 80 r / min during the soaking process to remove impurities on the fiber surface, and then dry it in an oven at 80 °C for 3 hours; place the dried polypropylene fiber in an ultraviolet irradiation device and irradiate it with ultraviolet light with a wavelength of 365 nm for 2 hours; add carbon nanotubes to a 3 mol / L nitric acid solution, reflux and stir at 90 °C for 6 hours, then wash it with deionized water until neutral, and dry it in an oven at 100 °C; A2. Add sodium dodecylbenzenesulfonate with a mass fraction of 0.5% to absolute ethanol, mix nano-silica with absolute ethanol containing sodium dodecylbenzenesulfonate, disperse it ultrasonically with an ultrasonic disperser for 40 minutes, then add the acid-treated carbon nanotubes and continue to disperse ultrasonically for 30 minutes; add the polypropylene fiber to a high-speed mixer, and slowly add the ethanol solution dispersed with nano-silica and acid-treated carbon nanotubes under the condition of a stirring speed of 800 r / min, and add acrylamide monomer and potassium persulfate initiator and continue to stir for 2 hours; then add ethylene-butyl acrylate copolymer, raise the temperature to 200 °C, and continue to stir at this temperature for 3 hours, and keep the stirring speed at 800 r / min; the dosage ratio of the pretreated polypropylene fiber, nano-silica, acrylamide monomer, potassium persulfate, ethylene-butyl acrylate copolymer, and acid-treated carbon nanotubes is 100 g:10 g:5 g:1 g:5 g:1 g; A3. After the blending is completed, naturally cool the mixture to room temperature, and granulate the cooled mixture through a twin-screw extruder. The extrusion temperature is set to change in a gradient, zone 1 is 180 °C, zone 2 is 200 °C, zone 3 is 220 °C, zone 4 is 240 °C, and the head temperature is 250 °C. The granulated particles are dried in an oven at 100 °C for 3 hours to obtain the modified polypropylene fiber.

[0008] Ultraviolet irradiation promotes the generation of free radicals on the surface of polypropylene fibers. These free radicals have enhanced reactivity with the subsequently added modifiers and can bind more firmly. At the same time, it improves the light stability of the fibers to a certain extent, slows down the aging rate under long-term light exposure, and extends the service life of the material. During the high-temperature stirring process, some double bonds in the ethylene-butyl acrylate copolymer undergo grafting reactions with the free radicals generated on the main chain of the polypropylene fiber due to high temperature. The C-C bonds on the main chain of the polypropylene fiber break at high temperature to form free radical active sites. The double bonds in the ethylene-butyl acrylate copolymer molecules are attacked by free radicals, opening the double bonds and forming chemical bond connections with the polypropylene fiber, thus achieving grafting. Due to its small particle size and large specific surface area, nano-silica can fill the microscopic defects inside the polypropylene fiber and is tightly combined with the polypropylene fiber through physical adsorption and chemical bonding, improving the strength and hardness of the fiber, and further enhancing the impact resistance and non-deformation performance. The butyl acrylate group in the molecular structure of the ethylene-butyl acrylate copolymer has a certain flexibility and polarity, which helps to improve the sound absorption ability of the fiber and improve the sound absorption performance.

[0009] Furthermore, the preparation steps of the modified vermiculite powder are as follows: B1. Immerse the vermiculite powder in a 3% sodium carbonate weak alkaline solution for 3 hours, stir continuously during the immersion process, rinse with a large amount of deionized water to neutrality after immersion, dry at 100 °C for 4 hours, and then sieve through a 300-mesh sieve to obtain vermiculite powder with uniform particle size; add nano-montmorillonite to deionized water and ultrasonically disperse for 20 minutes; add graphene oxide to deionized water and ultrasonically disperse for 2 hours; B2. Weigh silane coupling agent KH550, nano-zinc oxide, citric acid, deionized water, and graphene oxide after ultrasonic exfoliation treatment. First, add silane coupling agent KH550 to a beaker containing deionized water, set the stirring speed to 150 r / min, stir for 20 minutes, then add nano-zinc oxide, increase the stirring speed to 250 r / min, stir for 20 minutes, then add citric acid, stir at a speed of 200 r / min for 1 hour, and then add ultrasonically dispersed nano-montmorillonite and graphene oxide and continue to stir for 30 minutes to prepare the mixed solution required for modification; the dosage ratio of silane coupling agent KH550, nano-zinc oxide, citric acid, deionized water, nano-montmorillonite, and graphene oxide is 5 g: 2 g: 3 g: 85 g: 5 g: 2 g; B3. Slowly add the pretreated vermiculite powder into the mixed solution, keep the stirring speed at 200 r / min, seal the reaction vessel, carry out the reaction under a pressure environment of 0.15 MPa, heat up the mixed system to 50 °C and stir for 4 hours, perform microwave treatment every 1 hour, with a microwave power of 300 W and a treatment time of 10 minutes; after the reaction, filter the mixed solution through a Buchner funnel to separate the modified vermiculite powder, repeatedly wash the filtered vermiculite powder with deionized water until the washing liquid is neutral; put the washed vermiculite powder into an oven and dry it to constant weight at 90 °C to obtain the modified vermiculite powder; the dosage ratio of the pretreated vermiculite powder to the mixed solution is 8 g:100 g.

[0010] The alkoxy groups in the silane coupling agent molecule undergo hydrolysis reactions in aqueous solution, the Si-O-C bonds in the alkoxy groups break, and an exchange occurs with H-OH in water molecules to generate silanols and corresponding alcohols. Through dehydration condensation reactions between multiple silanol molecules, the O-H in the Si-OH bond breaks, the hydrogen atom combines with the hydroxyl group in other silanol molecules to form water, and the silicon atoms are connected through Si-O-Si bonds, gradually forming an organosilicon film with a three-dimensional network structure on the surface of the vermiculite powder. Vermiculite powder is mainly composed of layered silicate minerals, and its crystal structure contains various metal ions. The citric acid molecule contains multiple carboxyl groups, and the C=O double bond and O-H bond in the carboxyl group have certain polarity. During the reaction, the O-H bond in the carboxyl group breaks, the hydrogen ion leaves, and the carboxylate anion undergoes a complexation reaction with the metal ions in the vermiculite powder. The metal ions provide empty orbitals, and the oxygen atom in the carboxylate anion provides lone pair electrons to form stable coordination bonds, thereby enhancing the structural stability of the vermiculite powder. In a high-temperature environment, these complexes will undergo decomposition reactions to produce non-combustible gases such as carbon dioxide, playing a flame-retardant role. There are unsaturated Zn 2+ ions and lattice oxygen defects on the surface of nano-zinc oxide. During the mixing process with vermiculite powder, it can be firmly loaded on the surface of the vermiculite powder through electrostatic and chemical bonding effects. The photocatalytic activity of nano-zinc oxide stems from the fact that under light irradiation, valence band electrons are excited and transition to the conduction band, forming photo-generated electron-hole pairs. These electron-hole pairs can react with oxygen and water adsorbed on the surface of nano-zinc oxide to generate highly oxidizing hydroxyl radicals and superoxide anion radicals. These radicals can effectively decompose the cell walls and cell membranes of bacteria, molds and other microorganisms, playing an antibacterial role, and also contributing to the degradation of harmful organic substances in the air, improving the comprehensive performance of the vermiculite powder.

[0011] Further, the binder is one of acrylic emulsion and polyurethane emulsion.

[0012] Further, the waterproof agent is one of organosilicon waterproof agent, acrylate waterproof agent and polyurethane waterproof agent.

[0013] Further, the moisture-permeable agent is one of silicone moisture-permeable agent, polyethylene glycol, and glycerol.

[0014] Further, the electromagnetic shielding filler is one of carbonyl iron powder, nano silver powder, and graphite powder.

[0015] Further, the flame retardant is one of magnesium hydroxide and antimony trioxide; the dispersant is one of sodium polyacrylate, fatty acid polyoxyethylene ester, and sodium hexametaphosphate.

[0016] A preparation method of a lightweight sound insulation material comprises the following specific steps: S1. Preparation of mixed material A: Set the stirring speed of the high-speed mixer at 600 - 800 r / min. Add modified polypropylene fiber, hollow glass microspheres, wollastonite powder, nano-titanium dioxide, and dispersant into the high-speed mixer. Stir for 10 minutes after adding each material and then add the new material. After all materials are added, continue to stir for 30 - 45 minutes to make each component evenly mixed. S2. Preparation of mixed material B: Add modified vermiculite powder, ethylene-vinyl acetate copolymer latex powder, binder, waterproof agent, moisture-permeable agent, electromagnetic shielding filler, and flame retardant into another stirring container. Stir at a low speed with a stirring speed of 200 - 300 r / min. Stir for 10 minutes after adding each material and then add the new material. After all materials are added, continue to stir for 30 - 45 minutes to ensure that each component is fully mixed. S3. Co - extrusion: Add mixed material A and mixed material B into a twin - screw extruder. Set the temperature of the twin - screw extruder as follows: zone 1 at 160 °C, zone 2 at 180 °C, zone 3 at 200 °C, zone 4 at 220 °C, and the head temperature at 230 °C. Control the screw speed at 300 r / min. The materials go through the processes of melting, mixing, and extrusion in the extruder. The extrudate is cooled by a 15 °C water cooling tank and then cut into uniform particles of 2 - 4 mm by a pelletizer to obtain lightweight sound insulation material particles. The present invention provides a lightweight sound insulation material and its preparation method, having the following beneficial effects: 1. Hollow glass microspheres and modified polypropylene fiber are the key factors for realizing the lightweight of the material. The interior of the hollow glass microspheres is a hollow structure, with light self - weight, evenly dispersed in the material, effectively reducing the overall density. After specific pretreatment and co - blending modification, the internal structure of the modified polypropylene fiber changes. Combining with the hollow structure of the hollow glass microspheres, the two work together to set multiple obstacles for the propagation of sound waves. At the same time, the porous structure of the modified vermiculite powder also has a good absorption and scattering effect on sound waves. It can effectively block and absorb external noise, significantly improving the indoor acoustic environment quality.

[0017] 2. Nano-silica has a small particle size and a large specific surface area. During the blending and modification process with polypropylene fibers, it can fill the microscopic defects inside the fibers and tightly bind to the polypropylene fibers through physical adsorption and chemical bonding, greatly improving the strength and hardness of the fibers. This directly enhances the impact resistance and non-deformation properties of the material. The modified vermiculite powder forms an organosilicon film on its surface through the action of silane coupling agent, nano-zinc oxide, citric acid, etc., enhancing the structural stability.

[0018] 3. Nano-titanium dioxide and nano-zinc oxide play an important antibacterial role in the material. There are unsaturated zinc ions and lattice oxygen defects on the surface of nano-zinc oxide. Under light irradiation, valence band electrons transition to form photo-generated electron-hole pairs, which react with adsorbed oxygen and water to produce strongly oxidizing hydroxyl radicals and superoxide anion radicals, capable of effectively decomposing the cell walls and cell membranes of microorganisms such as bacteria and molds. At the same time, nano-titanium dioxide also has photocatalytic activity, which helps to degrade harmful organic substances in the air, making the material more environmentally friendly. The addition of waterproof agents, such as organosilicon waterproof agents, acrylate waterproof agents, etc., forms a waterproof barrier on the material surface. The moisture permeable agent ensures the water vapor exchange of the material in a humid environment, the electromagnetic shielding filler endows the material with electromagnetic shielding function, and the flame retardant improves the fire resistance of the material, meeting the usage requirements of various scenarios. Specific implementation mode

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0020] Example 1. Preparation of modified polypropylene fibers, the specific steps are as follows: A1. Immerse the polypropylene fibers in an acetone solution for 4 hours, stir during the immersion process at a speed of 80 r / min to remove impurities on the fiber surface, and then dry in an oven at 80 °C for 3 hours; place the dried polypropylene fibers in an ultraviolet irradiation device and irradiate with ultraviolet light with a wavelength of 365 nm for 2 hours; add carbon nanotubes to a 3 mol / L nitric acid solution, reflux and stir at 90 °C for 6 hours, then wash with deionized water until neutral, and dry in an oven at 100 °C; A2. Add sodium dodecylbenzenesulfonate with a mass fraction of 0.5% to absolute ethanol. Mix 10 g of nano-silica with the absolute ethanol containing sodium dodecylbenzenesulfonate, and ultrasonically disperse for 40 minutes using an ultrasonic disperser. Then add 1 g of acid-treated carbon nanotubes and continue to ultrasonically disperse for 30 minutes. Add 100 g of polypropylene fibers to a high-speed mixer. Under the condition of a stirring speed of 800 r / min, slowly add the ethanol solution dispersed with nano-silica and acid-treated carbon nanotubes, and add 5 g of acrylamide monomer and 1 g of potassium persulfate initiator and continuously stir for 2 hours. Then add 5 g of ethylene-butyl acrylate copolymer, heat up to 200 °C, and continue to stir at this temperature for 3 hours, with the stirring speed maintained at 800 r / min. A3. After the blending is completed, naturally cool the mixture to room temperature. Granulate the cooled mixture through a twin-screw extruder. The extrusion temperature is set to change in a gradient, with zone 1 at 180 °C, zone 2 at 200 °C, zone 3 at 220 °C, zone 4 at 240 °C, and the die head temperature at 250 °C. Dry the granulated particles in an oven at 100 °C for 3 hours to obtain modified polypropylene fibers.

[0021] Example 2. Prepare modified vermiculite powder, and the specific steps are as follows: B1. Immerse vermiculite powder in a sodium carbonate weak alkaline solution with a mass fraction of 3% for 3 hours, continuously stir during the immersion process, rinse with a large amount of deionized water to neutrality after immersion, dry at 100 °C for 4 hours, and then screen through a 300-mesh sieve to obtain vermiculite powder with uniform particle size. Add nano-montmorillonite to deionized water and ultrasonically disperse for 20 minutes. Add graphene oxide to deionized water and ultrasonically disperse for 2 hours. B2. Weigh 5 g of silane coupling agent KH550, 2 g of nano-zinc oxide, 3 g of citric acid, 85 g of deionized water, and 2 g of ultrasonically exfoliated graphene oxide. First, add the silane coupling agent KH550 to a beaker containing deionized water, set the stirring speed to 150 r / min, and stir for 20 minutes. Then add nano-zinc oxide, increase the stirring speed to 250 r / min, and stir for 20 minutes. Then add citric acid and stir at a speed of 200 r / min for 1 hour. Then add the ultrasonically dispersed nano-montmorillonite and graphene oxide and continue to stir for 30 minutes to obtain the mixed solution required for modification. B3. Slowly add 8 g of pretreated vermiculite powder into the mixed solution, keep the stirring speed at 200 r / min, seal the reaction vessel, carry out the reaction under a pressure environment of 0.15 MPa, heat up the mixed system to 50 °C and stir for 4 hours, perform microwave treatment every 1 hour, with a microwave power of 300 W and a treatment time of 10 minutes; after the reaction is completed, filter the mixed solution through a Buchner funnel to separate the modified vermiculite powder, repeatedly wash the filtered vermiculite powder with deionized water until the washing liquid is neutral; put the washed vermiculite powder into an oven and dry it to constant weight at 90 °C to obtain the modified vermiculite powder.

[0022] Example 3. Preparation of a lightweight sound insulation material, the specific steps are as follows: S1. Preparation of mixed material A: Set the stirring speed of the high-speed mixer at 600 r / min, add 18 parts of modified polypropylene fiber, 8 parts of hollow glass microspheres, 6 parts of wollastonite powder, 3 parts of nano-titanium dioxide, and 1 part of sodium polyacrylate into the high-speed mixer. Stir for 10 minutes after adding each material and then add the new material. After all are added, continue to stir for 30 minutes to make each component evenly mixed; S2. Preparation of mixed material B: Add 12 parts of modified vermiculite powder, 4 parts of ethylene-vinyl acetate copolymer latex powder, 10 parts of acrylic emulsion, 1 part of silicone waterproofing agent, 0.5 part of silicone moisture permeable agent, 4 parts of carbonyl iron powder filler, and 3 parts of magnesium hydroxide into another stirring container, and use low-speed stirring with a stirring speed of 200 r / min. Stir for 10 minutes after adding each material and then add the new material. After all are added, continue to stir for 30 minutes to ensure that each component is fully mixed; S3. Co-blending and extrusion: Add mixed material A and mixed material B into a twin-screw extruder. The temperature of the twin-screw extruder is set as follows: zone 1 at 160 °C, zone 2 at 180 °C, zone 3 at 200 °C, zone 4 at 220 °C, and the head temperature at 230 °C. The screw speed is controlled at 300 r / min. The materials go through the processes of melting, mixing, and extrusion in the extruder. The extrudate is cooled by a 15 °C water cooling tank and then cut into 2 mm uniform particles by a pelletizer to obtain lightweight sound insulation material particles.

[0023] Example 4. Preparation of a lightweight sound insulation material, the specific steps are as follows: S1. Preparation of mixed material A: Set the stirring speed of the high-speed mixer at 800 r / min, add 22 parts of modified polypropylene fiber, 12 parts of hollow glass microspheres, wollastonite powder, 5 parts of nano-titanium dioxide, and 3 parts of fatty acid polyoxyethylene ester into the high-speed mixer. Stir for 10 minutes after adding each material and then add the new material. After all are added, continue to stir for 45 minutes to make each component evenly mixed; S2. Preparation of Mixed Material B: Add 16 parts of modified vermiculite powder, 6 parts of vinyl acetate-ethylene copolymer latex powder, 14 parts of polyurethane emulsion, 3 parts of acrylate waterproofing agent, 1.5 parts of polyethylene glycol, 6 parts of nano silver powder, and 6 parts of antimony trioxide into another stirring container, and stir at a low speed with a stirring speed of 300 r / min. Stir for 10 minutes after adding each material and then add the new material. After all materials are added, continue to stir for 45 minutes to ensure that all components are fully mixed; S3. Co - extrusion: Add Mixed Material A and Mixed Material B into a twin - screw extruder. The temperature of the twin - screw extruder is set as follows: Zone 1 at 160 °C, Zone 2 at 180 °C, Zone 3 at 200 °C, Zone 4 at 220 °C, and the head temperature at 230 °C. The screw speed is controlled at 300 r / min. The materials go through the processes of melting, mixing, and extrusion in the extruder. The extrudate is cooled by a 15 °C water - cooling tank and then cut into 4 - mm uniform particles by a pelletizer to obtain lightweight sound - insulating material particles.

[0024] Example 5. Preparation of lightweight sound - insulating material, the specific steps are as follows: S1. Preparation of Mixed Material A: Set the stirring speed of the high - speed mixer at 700 r / min. Add 20 parts of modified polypropylene fiber, 10 parts of hollow glass microspheres, 7 parts of wollastonite powder, 4 parts of nano titanium dioxide, and 2 parts of sodium hexametaphosphate into the high - speed mixer. Stir for 10 minutes after adding each material and then add the new material. After all materials are added, continue to stir for 37 minutes to make all components evenly mixed; S2. Preparation of Mixed Material B: Add 14 parts of modified vermiculite powder, 5 parts of vinyl acetate - ethylene copolymer latex powder, 12 parts of polyurethane emulsion, 2 parts of polyurethane, 1 part of glycerol, 5 parts of graphite powder, and 4 parts of antimony trioxide into another stirring container, and stir at a low speed with a stirring speed of 250 r / min. Stir for 10 minutes after adding each material and then add the new material. After all materials are added, continue to stir for 37 minutes to ensure that all components are fully mixed; S3. Co - extrusion: Add Mixed Material A and Mixed Material B into a twin - screw extruder. The temperature of the twin - screw extruder is set as follows: Zone 1 at 160 °C, Zone 2 at 180 °C, Zone 3 at 200 °C, Zone 4 at 220 °C, and the head temperature at 230 °C. The screw speed is controlled at 300 r / min. The materials go through the processes of melting, mixing, and extrusion in the extruder. The extrudate is cooled by a 15 °C water - cooling tank and then cut into 3 - mm uniform particles by a pelletizer to obtain lightweight sound - insulating material particles.

[0025] Comparative Example 1 Keep the other steps unchanged, only replace the modified polypropylene fiber in Example 4 with untreated polypropylene fiber to prepare the sound - insulating material.

[0026] Comparative Example 2 The remaining steps remain unchanged. Only replace the modified vermiculite powder in Example 4 with unprocessed modified vermiculite powder to prepare the sound insulation material.

[0027] Test Items Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 <![CDATA[Density (g / cm 3 )]]> 0.82 0.88 0.86 0.95 0.92 Sound Insulation (1000 Hz) (dB) 30 35 34 25 28 Sound Absorption Coefficient (Average of 100 - 1000 Hz) 0.52 0.60 0.57 0.40 0.45 Impact Strength (J / m) 42 50 46 30 35 Tensile Strength (MPa) 11 14 13 8 10 Anti - Aging Performance (Retention Rate of Tensile Strength after 1000 h of Artificial Accelerated Aging) (%) 83 90 87 60 70 Antibacterial Rate (against Escherichia coli) (%) 94 97 96 70 80 Waterproof Performance (Water Absorption Rate) (%) 3.5 2 2.8 8 6 Electromagnetic Shielding Effectiveness (Average of 100 MHz - 1 GHz) (dB) 16 22 20 5 10 Fire - proof Performance (Oxygen Index) (%) 28 35 33 20 25 In terms of density, the values of Examples 3-5 are in the range of 0.82−0.88 g / cm 3 , which is lower than that of Comparative Example 1 and Comparative Example 2. This indicates that components such as hollow glass microspheres and modified polypropylene fibers used in the material have successfully achieved the lightweight of the material. In terms of sound insulation and sound absorption coefficients, the examples are significantly better than the comparative examples. The sound insulation of Example 4 reaches 35 dB at 1000 Hz, and the average sound absorption coefficient is 0.60, reflecting the significant effect of modified polypropylene fibers and vermiculite powder on improving sound insulation and sound absorption performance. In terms of mechanical properties, whether it is impact strength or tensile strength, the examples are higher than the comparative examples, indicating that the modified materials have great advantages in durability. In the anti-aging performance test, after 1000 h of artificial accelerated aging, the tensile strength retention rate of the examples is 83%-90%, while those of Comparative Example 1 and Comparative Example 2 are 60% and 70% respectively, indicating that components such as modified vermiculite powder enhance the anti-aging ability of the material. In terms of antibacterial performance, the antibacterial rate of the examples against Escherichia coli is 94%-97%, which is much higher than that of the comparative examples. Nano-titanium dioxide and nano-zinc oxide etc. play an important antibacterial role. In terms of waterproof performance, the water absorption rate of the examples is 2%-3.5%, while those of the comparative examples are 8% and 6% respectively, indicating that the addition of waterproof agents makes the material have better waterproof performance. In terms of electromagnetic shielding effectiveness, the examples reach 16-22 dB on average in the range of 100 MHz - 1 GHz, which is significantly higher than that of the comparative examples, indicating that the addition of electromagnetic shielding fillers endows the material with good electromagnetic shielding ability. The fire resistance test shows that the oxygen index of the examples is 28%-35%, while those of the comparative examples are 20% and 25% respectively. The use of modified vermiculite powder and flame retardants improves the fire resistance of the material.

[0028] The above content is only an example and illustration of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them. As long as they do not deviate from the invention or exceed the scope defined by this claims, they should all belong to the protection scope of the present invention.

Claims

1. A lightweight sound insulation material, characterized in that: The invention comprises the following raw materials in parts by weight: 18-22 parts of modified polypropylene fiber, 12-16 parts of modified vermiculite powder, 3-5 parts of nano titanium dioxide, 8-12 parts of hollow glass microspheres, 6-8 parts of wollastonite powder, 4-6 parts of vinyl acetate-ethylene copolymer latex powder, 10-14 parts of adhesive, 1-3 parts of waterproofing agent, 0.5-1.5 parts of moisture permeability agent, 4-6 parts of electromagnetic shielding filler, 3-5 parts of flame retardant and 1-3 parts of dispersant.

2. A lightweight sound insulation material according to claim 1, characterized in that: The modified polypropylene fiber is specifically prepared in the following steps: A1. Soak the polypropylene fiber in an acetone solution for 4 hours, stirring at a speed of 80 r / min during the soaking process to remove impurities on the fiber surface, and then dry it in an oven at 80°C for 3 hours; place the dried polypropylene fiber in an ultraviolet irradiation device and irradiate it with ultraviolet rays with a wavelength of 365 nm for 2 hours; The carbon nanotubes were added to a 3 mol / L nitric acid solution, refluxed and stirred at 90°C for 6 hours, then washed with deionized water until neutral, and dried in an oven at 100°C; A2. Add 0.5% sodium dodecylbenzene sulfonate by mass to anhydrous ethanol, mix nano-silica with anhydrous ethanol containing sodium dodecylbenzene sulfonate, use an ultrasonic disperser to ultrasonically disperse for 40 minutes, then add the carbon nanotubes treated by acidification, and continue ultrasonically disperse for 30 minutes; add polypropylene fiber to a high-speed mixer, slowly add the ethanol solution dispersed with nano-silica and the carbon nanotubes treated by acidification at a stirring speed of 800 r / min, and add acrylamide monomer and potassium persulfate initiator to continue stirring for 2 hours; then add ethylene-butyl acrylate copolymer, heat to 200°C, continue stirring at this temperature for 3 hours, and keep the stirring speed at 800 r / min; the amount ratio of pretreated polypropylene fiber, nano-silica, acrylamide monomer, potassium persulfate, ethylene-butyl acrylate copolymer, and acidified carbon nanotubes is 100g:10g:5g:1g:5g:1g; A3. After the blending is completed, the mixture is naturally cooled to room temperature, and the cooled mixture is granulated by a twin-screw extruder. The extrusion temperature is set to a gradient change, 180°C in zone 1, 200°C in zone 2, 220°C in zone 3, 240°C in zone 4, and the head temperature is 250°C. The granulated particles are dried in an oven at 100°C for 3 hours to obtain modified polypropylene fibers.

3. A lightweight sound insulation material according to claim 1, characterized in that: The modified vermiculite powder is specifically prepared in the following steps: B1. Soak the vermiculite powder in a weak alkaline solution of sodium carbonate with a mass fraction of 3% for 3 hours, stirring continuously during the soaking process, rinse with a large amount of deionized water until neutral, dry at 100° C. for 4 hours, and then sieve through a 300-mesh sieve to obtain vermiculite powder with uniform particle size; add nano-montmorillonite to deionized water and ultrasonically disperse for 20 minutes; add graphene oxide to deionized water and ultrasonicate for 2 hours; B2. Weigh silane coupling agent KH550, nano zinc oxide, citric acid, deionized water and graphene oxide treated with ultrasonic exfoliation. First, add silane coupling agent KH550 to a beaker with deionized water, set the stirring speed to 150 r / min, stir for 20 minutes, then add nano zinc oxide, increase the stirring speed to 250 r / min, stir for 20 minutes, then add citric acid, stir at a speed of 200 r / min for 1 hour, then add nano montmorillonite and graphene oxide after ultrasonic dispersion and continue stirring for 30 minutes to obtain a mixed solution required for modification; the amount ratio of silane coupling agent KH550, nano zinc oxide, citric acid, deionized water, nano montmorillonite and graphene oxide is 5g:2g:3g:85g:5g:2g; B3. Slowly add the pretreated vermiculite powder to the mixed solution, keep the stirring speed at 200r / min, seal the reaction vessel, react under a pressure environment of 0.15MPa, heat the mixed system to 50℃ and stir for 4 hours, perform microwave treatment once every hour, the microwave power is 300W, and the treatment time is 10 minutes; after the reaction, filter the mixed solution through a Buchner funnel to separate the modified vermiculite powder, and repeatedly wash the filtered vermiculite powder with deionized water until the washing liquid is neutral; put the washed vermiculite powder into an oven, dry it at 90℃ to constant weight, and obtain modified vermiculite powder; the amount ratio of pretreated vermiculite powder to mixed solution is 8g:100g.

4. The lightweight sound insulation material according to claim 1, characterized in that: The adhesive is one of acrylic emulsion and polyurethane emulsion.

5. The lightweight sound insulation material according to claim 1, characterized in that: The waterproofing agent is one of an organic silicon waterproofing agent, an acrylate waterproofing agent, and a polyurethane waterproofing agent.

6. The lightweight sound insulation material according to claim 1, characterized in that: The moisture permeable agent is one of organic silicon moisture permeable agent, polyethylene glycol and glycerol.

7. The lightweight sound insulation material according to claim 1, characterized in that: The electromagnetic shielding filler is one of carbonyl iron powder, nano silver powder and graphite powder.

8. The lightweight sound insulation material according to claim 1, characterized in that: The flame retardant is one of magnesium hydroxide and antimony trioxide.

9. The lightweight sound insulation material according to claim 1, characterized in that: The dispersant is one of sodium polyacrylate, polyoxyethylene fatty acid ester and sodium hexametaphosphate.

10. A method for preparing a lightweight sound insulation material, comprising the following steps: S1, preparation of mixed material A: set the stirring speed of the high-speed mixer to 600-800r / min, add modified polypropylene fiber, hollow glass microspheres, wollastonite powder, nano titanium dioxide, and dispersant into the high-speed mixer, stir each material for 10 minutes after adding it, then add new material, and continue stirring for 30-45 minutes after all are added to make the components evenly mixed; S2, preparation of mixed material B: modified vermiculite powder, vinyl acetate-ethylene copolymer latex powder, binder, waterproof agent, moisture permeable agent, electromagnetic shielding filler, flame retardant are added to another stirring container, and stirred at a low speed of 200-300r / min. After each material is added, stir for 10 minutes before adding new materials. After all are added, continue stirring for 30-45 minutes to ensure that all components are fully mixed; S3. Co-blending extrusion: Add mixed material A and mixed material B into a twin-screw extruder. The temperature of the twin-screw extruder is set as follows: 160°C in zone 1, 180°C in zone 2, 200°C in zone 3, 220°C in zone 4, the die temperature is 230°C, and the screw speed is controlled at 300r / min. The materials undergo melting, mixing and extrusion processes in the extruder. The extrudate is cooled in a 15°C water-cooling tank and then cut into uniform particles of 2-4mm by a pelletizer to obtain lightweight sound insulation material particles.